Conventionally, an information presentation device is well known, for example, in JP-A-2007-55561. In the device, a vibration generating unit such as a motor with an eccentric weight is mounted on a part of a steering wheel, which is gripped by a driver of a vehicle when the vehicle runs in a straight line. The transmit device transmits the information by controlling a magnitude (i.e., a strength) of vibration and a time interval (or duration time) of vibration.
Another information presentation device for a vehicle is well known in JP-A-2008-77631. In the device, a vibrator is mounted on an acceleration pedal, another vibrator is mounted on a steering wheel, and multiple vibrators are mounted on a seat of the vehicle. Then, the vibrators function with each other so that apparent movement occurs. Thus, the transmit device informs the information.
Here, the apparent movement is phenomenon such that, when two or more stimulations are applied on different positions continuously at short time intervals, as if one stimulation is applied and displaced from one position to another position. Accordingly, two or more vibrators contact the driver or are arranged near the driver at the same time, and the vibrators have a certain positional relationship so that vibration from two or more vibrators is applied to the driver at the same time.
In view of the above techniques in JP-A-2008-77631 and JP-A-2007-55561, when the information is transmitted to the driver via the steering wheel, the information may not be transmitted since the grip position of the driver is changed in order to operate the steering wheel.
Specifically, only when multiple vibrators (i.e., vibration generators) contact the driver at the same time, the information having a directional property can be transmitted to the driver. Thus, if the driver grips a part of the steering wheel, at which the vibrator is not arranged, the information may not be transmitted to the driver.